I have a Volkswagen Transporter T4 with an 02b gearbox. It's very similar to the normal water-cooled VW manual (e.g. 02a and 02j) gearboxes.
It has begun to be intermittently difficult to shift into gear. It does not make any strange noises, such as a bearing whine.
The weird symptom
Engine running, when I put the car in neutral it will roll freely on a slight grade. Pressing the clutch and pushing it into gear (especially first) causes it to stop rolling as the synchro bites. To be extremely clear, this is all done while the engine is running, not stopped.
The input shaft must be significantly slowed somehow so that when the output synchro begins to press into the gear it acts like a brake. What reasons could cause this?
I experimented with it again tonight. Driving ~50 mph and shifting into 1st slowly (clutch depressed of course) does make it audibly whine once in gear. You can hear the input shaft spinning up as the synchro grabs before it finally goes into gear. Interestingly enough, it shifted smoother after this for a short while. Shifting into first, engine off, clutch depressed (and not released) during a slow roll also makes soft but expensive noises that sound like the drivetrain rocking against its mounts. I'm going to pull the transmission as soon as my schedule allows, but I suspect input shaft bearings.